How is gay marriage like skim milk? That question made for just one of the interesting moments in Wednesday's hearing on gay marriage at the Supreme Court. Here are five from the arguments today.Gay soldiers(AP)Justice Samuel Alito posed an interesting hypothetical case involving openly gay soldiers that would not have been possible until the Don't Ask Don't Tell rule was repealed in 2011."Let's say three soldiers are injured and they are all in same-sex relationships, and in each instance the …